From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1ZPCj3-0003Dv-Ui for mharc-grub-devel@gnu.org; Tue, 11 Aug 2015 12:48:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43210) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZPCiy-00036R-9C for grub-devel@gnu.org; Tue, 11 Aug 2015 12:48:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZPCit-0006ac-1d for grub-devel@gnu.org; Tue, 11 Aug 2015 12:48:28 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:33416) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZPCis-0006Zo-Ni for grub-devel@gnu.org; Tue, 11 Aug 2015 12:48:22 -0400 Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id t7BGmCRZ011893 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 11 Aug 2015 16:48:13 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.13.8/8.13.8) with ESMTP id t7BGmCVr009880 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Tue, 11 Aug 2015 16:48:12 GMT Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by userv0121.oracle.com (8.13.8/8.13.8) with ESMTP id t7BGm8wx001623; Tue, 11 Aug 2015 16:48:09 GMT Received: from l.oracle.com (/10.137.176.158) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 11 Aug 2015 09:48:08 -0700 Received: by l.oracle.com (Postfix, from userid 1000) id BAA316A3C73; Tue, 11 Aug 2015 12:48:06 -0400 (EDT) Date: Tue, 11 Aug 2015 12:48:06 -0400 From: Konrad Rzeszutek Wilk To: Daniel Kiper Subject: Re: [Xen-devel] [PATCH v2 22/23] x86: make Xen early boot code relocatable Message-ID: <20150811164806.GB32231@l.oracle.com> References: <1437402558-7313-1-git-send-email-daniel.kiper@oracle.com> <1437402558-7313-23-git-send-email-daniel.kiper@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437402558-7313-23-git-send-email-daniel.kiper@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: userv0022.oracle.com [156.151.31.74] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 141.146.126.69 Cc: jgross@suse.com, grub-devel@gnu.org, keir@xen.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, andrew.cooper3@citrix.com, gang.wei@intel.com, roy.franz@linaro.org, ning.sun@intel.com, david.vrabel@citrix.com, jbeulich@suse.com, phcoder@gmail.com, xen-devel@lists.xenproject.org, wei.liu2@citrix.com, richard.l.maliszewski@intel.com, qiaowei.ren@intel.com, fu.wei@linaro.org X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Aug 2015 16:48:31 -0000 On Mon, Jul 20, 2015 at 04:29:17PM +0200, Daniel Kiper wrote: > Every multiboot protocol (regardless of version) compatible image must > specify its load address (in ELF or multiboot header). Multiboot protocol > compatible loader have to load image at specified address. However, there > is no guarantee that the requested memory region (in case of Xen it starts > at 1 MiB and ends at 17 MiB) where image should be loaded initially is a RAM > and it is free (legacy BIOS platforms are merciful for Xen but I found at > least one EFI platform on which Xen load address conflicts with EFI boot > services; it is Dell PowerEdge R820 with latest firmware). To cope with > that problem we must make Xen early boot code relocatable. This patch does > that. However, it does not add multiboot2 protocol interface which is done > in next patch. s/next patch/"x86: add multiboot2 protocol support for relocatable image." > > This patch changes following things: > - default load address is changed from 1 MiB to 2 MiB; I did that because > initial page tables are using 2 MiB huge pages and this way required > updates for them are quite easy; it means that e.g. we avoid spacial > cases for beginning and end of required memory region if it live at > address not aligned to 2 MiB, > - %ebp register is used as a storage for Xen image base address; this way > we can get this value very quickly if it is needed; however, %ebp register > is not used directly to access a given memory region, > - %fs register is filled with segment descriptor which describes memory region > with Xen image (it could be relocated or not); it is used to access some of 'memory region with Xen image' ? Not sure I follow? Perhaps: segment descriptor which starts (0) at Xen image base (_start). > Xen data in early boot code; potentially we can use above mentioned segment > descriptor to access data using %ds:%esi and/or %es:%esi (e.g. movs*); however, > I think that it could unnecessarily obfuscate code (e.g. we need at least > to operations to reload a given segment descriptor) and current solution s/to/two/ ? > looks quite optimal. > > Signed-off-by: Daniel Kiper > --- > xen/arch/x86/Makefile | 6 +- > xen/arch/x86/Rules.mk | 4 + > xen/arch/x86/boot/head.S | 165 ++++++++++++++++++++++++++++++---------- > xen/arch/x86/boot/trampoline.S | 11 ++- > xen/arch/x86/boot/wakeup.S | 6 +- > xen/arch/x86/boot/x86_64.S | 34 ++++----- > xen/arch/x86/setup.c | 33 ++++---- > xen/arch/x86/x86_64/mm.c | 2 +- > xen/arch/x86/xen.lds.S | 2 +- > xen/include/asm-x86/config.h | 3 + > xen/include/asm-x86/page.h | 2 +- > 11 files changed, 182 insertions(+), 86 deletions(-) > > diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile > index 82c5a93..93069a8 100644 > --- a/xen/arch/x86/Makefile > +++ b/xen/arch/x86/Makefile > @@ -72,8 +72,10 @@ efi-$(x86_64) := $(shell if [ ! -r $(BASEDIR)/include/xen/compile.h -o \ > echo '$(TARGET).efi'; fi) > > $(TARGET): $(TARGET)-syms $(efi-y) boot/mkelf32 > - ./boot/mkelf32 $(TARGET)-syms $(TARGET) 0x100000 \ > - `$(NM) -nr $(TARGET)-syms | head -n 1 | sed -e 's/^\([^ ]*\).*/0x\1/'` > +# THIS IS UGLY HACK! PLEASE DO NOT COMPLAIN. I WILL FIX IT IN NEXT RELEASE. OK :-) > + ./boot/mkelf32 $(TARGET)-syms $(TARGET) $(XEN_IMG_PHYS_START) 0xffff82d081000000 > +# ./boot/mkelf32 $(TARGET)-syms $(TARGET) 0x100000 \ > +# `$(NM) -nr $(TARGET)-syms | head -n 1 | sed -e 's/^\([^ ]*\).*/0x\1/'` > > > ALL_OBJS := $(BASEDIR)/arch/x86/boot/built_in.o $(BASEDIR)/arch/x86/efi/built_in.o $(ALL_OBJS) > diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk > index 4a04a8a..7ccb8a0 100644 > --- a/xen/arch/x86/Rules.mk > +++ b/xen/arch/x86/Rules.mk > @@ -15,6 +15,10 @@ HAS_GDBSX := y > HAS_PDX := y > xenoprof := y > > +XEN_IMG_PHYS_START = 0x200000 > + > +CFLAGS += -DXEN_IMG_PHYS_START=$(XEN_IMG_PHYS_START) > + > CFLAGS += -I$(BASEDIR)/include > CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic > CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default > diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S > index 3f1054d..d484f68 100644 > --- a/xen/arch/x86/boot/head.S > +++ b/xen/arch/x86/boot/head.S > @@ -12,13 +12,15 @@ > .text > .code32 > > -#define sym_phys(sym) ((sym) - __XEN_VIRT_START) > +#define sym_phys(sym) ((sym) - __XEN_VIRT_START + XEN_IMG_PHYS_START - XEN_IMG_OFFSET) > +#define sym_offset(sym) ((sym) - __XEN_VIRT_START) > > #define BOOT_CS32 0x0008 > #define BOOT_CS64 0x0010 > #define BOOT_DS 0x0018 > #define BOOT_PSEUDORM_CS 0x0020 > #define BOOT_PSEUDORM_DS 0x0028 > +#define BOOT_FS 0x0030 > > #define MB2_HT(name) (MULTIBOOT2_HEADER_TAG_##name) > #define MB2_TT(name) (MULTIBOOT2_TAG_TYPE_##name) > @@ -105,12 +107,13 @@ multiboot1_header_end: > > .word 0 > gdt_boot_descr: > - .word 6*8-1 > - .long sym_phys(trampoline_gdt) > + .word 7*8-1 > +gdt_boot_descr_addr: > + .long sym_offset(trampoline_gdt) > .long 0 /* Needed for 64-bit lgdt */ > > cs32_switch_addr: > - .long sym_phys(cs32_switch) > + .long sym_offset(cs32_switch) > .word BOOT_CS32 > > .Lbad_cpu_msg: .asciz "ERR: Not a 64-bit CPU!" > @@ -120,13 +123,13 @@ cs32_switch_addr: > .section .init.text, "ax", @progbits > > bad_cpu: > - mov $(sym_phys(.Lbad_cpu_msg)),%esi # Error message > + lea sym_offset(.Lbad_cpu_msg)(%ebp),%esi # Error message > jmp print_err > not_multiboot: > - mov $(sym_phys(.Lbad_ldr_msg)),%esi # Error message > + lea sym_offset(.Lbad_ldr_msg)(%ebp),%esi # Error message > jmp print_err > mb2_too_old: > - mov $(sym_phys(.Lbad_mb2_ldr)),%esi # Error message > + lea sym_offset(.Lbad_mb2_ldr)(%ebp),%esi # Error message > print_err: > mov $0xB8000,%edi # VGA framebuffer > 1: mov (%esi),%bl > @@ -151,6 +154,9 @@ print_err: > __efi64_start: > cld > > + /* Load default Xen image base address. */ > + mov $sym_phys(__image_base__),%ebp > + > /* Check for Multiboot2 bootloader. */ > cmp $MULTIBOOT2_BOOTLOADER_MAGIC,%eax > je efi_multiboot2_proto > @@ -235,9 +241,11 @@ x86_32_switch: > cli > > /* Initialise GDT. */ > + add %ebp,gdt_boot_descr_addr(%rip) > lgdt gdt_boot_descr(%rip) > > /* Reload code selector. */ > + add %ebp,cs32_switch_addr(%rip) > ljmpl *cs32_switch_addr(%rip) > > .code32 > @@ -263,12 +271,8 @@ __start: > cld > cli > > - /* Initialise GDT and basic data segments. */ > - lgdt %cs:sym_phys(gdt_boot_descr) > - mov $BOOT_DS,%ecx > - mov %ecx,%ds > - mov %ecx,%es > - mov %ecx,%ss > + /* Load default Xen image base address. */ > + mov $sym_phys(__image_base__),%ebp > > /* Bootloaders may set multiboot{1,2}.mem_lower to a nonzero value. */ > xor %edx,%edx > @@ -319,6 +323,19 @@ multiboot2_proto: > jmp 0b > > trampoline_bios_setup: > + mov %ebp,%esi > + > + /* Initialise GDT and basic data segments. */ > + add %ebp,sym_offset(gdt_boot_descr_addr)(%esi) > + lgdt sym_offset(gdt_boot_descr)(%esi) > + > + mov $BOOT_DS,%ecx > + mov %ecx,%ds > + mov %ecx,%es > + mov %ecx,%fs > + mov %ecx,%gs > + mov %ecx,%ss > + The non-EFI boot path is now: start \- __start \- multiboot2_proto | jmp trampoline_bios_setup | \-and if not MB2: jmp trampoline_bios_setup. In here you tweak the GDT and reload the %ds - but during this call chain we do touch the %ds - via: __start+27>: testb $0x1,(%rbx) __start+30>: cmovne 0x4(%rbx),%edx which is OK (as MB1 says that the %ds has to cover up to 4GB). But I wonder why the __start code had the segments reloaded so early? Was the bootloader not setting the proper segments? Let me double-check what SYSLINUX's mboot.c32 does. Perhaps it had done something odd in the past. > /* Set up trampoline segment 64k below EBDA */ > movzwl 0x40e,%ecx /* EBDA segment */ > cmp $0xa000,%ecx /* sanity check (high) */ > @@ -340,33 +357,58 @@ trampoline_bios_setup: > cmovb %edx,%ecx /* and use the smaller */ > > trampoline_setup: Would it make sense to add: /* Gets called from EFI (from x86_32_switch) and legacy (see above) boot loaders. */ > + mov %ebp,%esi > + > + /* Initialize 0-15 bits of BOOT_FS segment descriptor base address. */ > + mov %ebp,%edx > + shl $16,%edx > + or %edx,(sym_offset(trampoline_gdt)+BOOT_FS)(%esi) > + > + /* Initialize 16-23 bits of BOOT_FS segment descriptor base address. */ > + mov %ebp,%edx > + shr $16,%edx > + and $0x000000ff,%edx > + or %edx,(sym_offset(trampoline_gdt)+BOOT_FS+4)(%esi) > + > + /* Initialize 24-31 bits of BOOT_FS segment descriptor base address. */ > + mov %ebp,%edx > + and $0xff000000,%edx > + or %edx,(sym_offset(trampoline_gdt)+BOOT_FS+4)(%esi) > + > + /* Initialize %fs and later use it to access Xen data if possible. */ > + mov $BOOT_FS,%edx > + mov %edx,%fs > + We just modified the GDT. Should we reload it (lgdt?)? > /* Reserve 64kb for the trampoline. */ > sub $0x1000,%ecx > > /* From arch/x86/smpboot.c: start_eip had better be page-aligned! */ > xor %cl, %cl > shl $4, %ecx > - mov %ecx,sym_phys(trampoline_phys) > + mov %ecx,%fs:sym_offset(trampoline_phys) > + > + /* Save Xen image base address for later use. */ > + mov %ebp,%fs:sym_offset(xen_img_base_phys_addr) > > /* Save the Multiboot info struct (after relocation) for later use. */ > - mov $sym_phys(cpu0_stack)+1024,%esp > + lea (sym_offset(cpu0_stack)+1024)(%ebp),%esp > push %eax /* Multiboot magic. */ > push %ebx /* Multiboot information address. */ > push %ecx /* Boot trampoline address. */ > call reloc > add $12,%esp /* Remove reloc() args from stack. */ > - mov %eax,sym_phys(multiboot_ptr) > + mov %eax,%fs:sym_offset(multiboot_ptr) > > /* > * Do not zero BSS on EFI platform here. > * It was initialized earlier. > */ > - cmpb $1,sym_phys(skip_realmode) > + cmpb $1,%fs:sym_offset(skip_realmode) > je 1f > > /* Initialize BSS (no nasty surprises!). */ > - mov $sym_phys(__bss_start),%edi > - mov $sym_phys(__bss_end),%ecx > + lea sym_offset(__bss_start)(%ebp),%edi > + lea sym_offset(__bss_end)(%ebp),%ecx > sub %edi,%ecx > shr $2,%ecx > xor %eax,%eax > @@ -381,8 +423,8 @@ trampoline_setup: > jbe 1f > mov $0x80000001,%eax > cpuid > -1: mov %edx,sym_phys(cpuid_ext_features) > - mov %edx,sym_phys(boot_cpu_data)+CPUINFO_FEATURE_OFFSET(X86_FEATURE_LM) > +1: mov %edx,%fs:sym_offset(cpuid_ext_features) > + mov %edx,%fs:(sym_offset(boot_cpu_data)+CPUINFO_FEATURE_OFFSET(X86_FEATURE_LM)) > > /* Check for availability of long mode. */ > bt $X86_FEATURE_LM & 0x1f,%edx > @@ -390,72 +432,111 @@ trampoline_setup: > > /* Stash TSC to calculate a good approximation of time-since-boot */ > rdtsc > - mov %eax,sym_phys(boot_tsc_stamp) > - mov %edx,sym_phys(boot_tsc_stamp+4) > + mov %eax,%fs:sym_offset(boot_tsc_stamp) > + mov %edx,%fs:sym_offset(boot_tsc_stamp+4) > > - /* Initialise L2 boot-map page table entries (16MB). */ > - mov $sym_phys(l2_bootmap),%edx > - mov $PAGE_HYPERVISOR|_PAGE_PSE,%eax > - mov $8,%ecx > + /* Update frame addreses in page tables. */ > + lea sym_offset(__page_tables_start)(%ebp),%edx > + mov $((__page_tables_end-__page_tables_start)/8),%ecx > +1: testl $_PAGE_PRESENT,(%edx) > + jz 2f > + add %ebp,(%edx) > +2: add $8,%edx > + loop 1b > + > + /* Initialise L2 boot-map page table entries (14MB). */ > + lea sym_offset(l2_bootmap)(%ebp),%edx > + lea sym_offset(start)(%ebp),%eax > + and $~((1< + mov %eax,%ebx > + shr $(L2_PAGETABLE_SHIFT-3),%ebx > + and $(L2_PAGETABLE_ENTRIES*4*8-1),%ebx > + add %ebx,%edx > + add $(PAGE_HYPERVISOR|_PAGE_PSE),%eax > + mov $7,%ecx > 1: mov %eax,(%edx) > add $8,%edx > add $(1< loop 1b > + > /* Initialise L3 boot-map page directory entry. */ > - mov $sym_phys(l2_bootmap)+__PAGE_HYPERVISOR,%eax > - mov %eax,sym_phys(l3_bootmap) + 0*8 > + lea (sym_offset(l2_bootmap)+__PAGE_HYPERVISOR)(%ebp),%eax > + lea sym_offset(l3_bootmap)(%ebp),%ebx > + mov $4,%ecx > +1: mov %eax,(%ebx) > + add $8,%ebx > + add $(L2_PAGETABLE_ENTRIES*8),%eax > + loop 1b > + > + /* Initialise L2 direct map page table entries (14MB). */ > + lea sym_offset(l2_identmap)(%ebp),%edx > + lea sym_offset(start)(%ebp),%eax > + and $~((1< + mov %eax,%ebx > + shr $(L2_PAGETABLE_SHIFT-3),%ebx > + and $(L2_PAGETABLE_ENTRIES*4*8-1),%ebx > + add %ebx,%edx > + add $(PAGE_HYPERVISOR|_PAGE_PSE),%eax > + mov $7,%ecx > +1: mov %eax,(%edx) > + add $8,%edx > + add $(1< + loop 1b > + > /* Hook 4kB mappings of first 2MB of memory into L2. */ > - mov $sym_phys(l1_identmap)+__PAGE_HYPERVISOR,%edi > - mov %edi,sym_phys(l2_xenmap) > - mov %edi,sym_phys(l2_bootmap) > + lea (sym_offset(l1_identmap)+__PAGE_HYPERVISOR)(%ebp),%edi > + mov %edi,%fs:sym_offset(l2_bootmap) But not to l2_xenmap? > > /* Apply relocations to bootstrap trampoline. */ > - mov sym_phys(trampoline_phys),%edx > - mov $sym_phys(__trampoline_rel_start),%edi > + mov %fs:sym_offset(trampoline_phys),%edx > + lea sym_offset(__trampoline_rel_start)(%ebp),%edi > + lea sym_offset(__trampoline_rel_stop)(%ebp),%esi > 1: > mov (%edi),%eax > add %edx,(%edi,%eax) > add $4,%edi > - cmp $sym_phys(__trampoline_rel_stop),%edi > + cmp %esi,%edi > jb 1b > > /* Patch in the trampoline segment. */ > shr $4,%edx > - mov $sym_phys(__trampoline_seg_start),%edi > + lea sym_offset(__trampoline_seg_start)(%ebp),%edi > + lea sym_offset(__trampoline_seg_stop)(%ebp),%esi > 1: > mov (%edi),%eax > mov %dx,(%edi,%eax) > add $4,%edi > - cmp $sym_phys(__trampoline_seg_stop),%edi > + cmp %esi,%edi > jb 1b > > /* Do not parse command line on EFI platform here. */ > - cmpb $1,sym_phys(skip_realmode) > + cmpb $1,%fs:sym_offset(skip_realmode) > je 1f > > /* Bail if there is no command line to parse. */ > - mov sym_phys(multiboot_ptr),%ebx > + mov %fs:sym_offset(multiboot_ptr),%ebx > testl $MBI_CMDLINE,MB_flags(%ebx) > jz 1f > > cmpl $0,MB_cmdline(%ebx) > jz 1f > > - pushl $sym_phys(early_boot_opts) > + lea sym_offset(early_boot_opts)(%ebp),%eax > + push %eax > pushl MB_cmdline(%ebx) > call cmdline_parse_early > add $8,%esp /* Remove cmdline_parse_early() args from stack. */ > > 1: > /* Switch to low-memory stack. */ > - mov sym_phys(trampoline_phys),%edi > + mov %fs:sym_offset(trampoline_phys),%edi > lea 0x10000(%edi),%esp > lea trampoline_boot_cpu_entry-trampoline_start(%edi),%eax > pushl $BOOT_CS32 > push %eax > > /* Copy bootstrap trampoline to low memory, below 1MB. */ > - mov $sym_phys(trampoline_start),%esi > + lea sym_offset(trampoline_start)(%ebp),%esi > mov $trampoline_end - trampoline_start,%ecx > rep movsb > > diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S > index 3c2714d..a8909ce 100644 > --- a/xen/arch/x86/boot/trampoline.S > +++ b/xen/arch/x86/boot/trampoline.S > @@ -52,12 +52,20 @@ trampoline_gdt: > /* 0x0028: real-mode data @ BOOT_TRAMPOLINE */ > .long 0x0000ffff > .long 0x00009200 > + /* > + * 0x0030: ring 0 Xen data, 16 MiB size, base > + * address is initialized during runtime. s/initialized/computed/ > + */ > + .quad 0x00c0920000001000 > > .pushsection .trampoline_rel, "a" > .long trampoline_gdt + BOOT_PSEUDORM_CS + 2 - . > .long trampoline_gdt + BOOT_PSEUDORM_DS + 2 - . > .popsection > > +GLOBAL(xen_img_base_phys_addr) > + .long 0 > + > GLOBAL(cpuid_ext_features) > .long 0 > > @@ -82,7 +90,8 @@ trampoline_protmode_entry: > mov %ecx,%cr4 > > /* Load pagetable base register. */ > - mov $sym_phys(idle_pg_table),%eax > + mov bootsym_rel(xen_img_base_phys_addr,4,%eax) > + lea sym_offset(idle_pg_table)(%eax),%eax > add bootsym_rel(trampoline_xen_phys_start,4,%eax) > mov %eax,%cr3 > > diff --git a/xen/arch/x86/boot/wakeup.S b/xen/arch/x86/boot/wakeup.S > index 08ea9b2..ff80f7f 100644 > --- a/xen/arch/x86/boot/wakeup.S > +++ b/xen/arch/x86/boot/wakeup.S > @@ -119,8 +119,10 @@ wakeup_32: > mov %eax, %ss > mov $bootsym_rel(wakeup_stack, 4, %esp) > > + mov bootsym_rel(xen_img_base_phys_addr, 4, %ebx) > + > # check saved magic again > - mov $sym_phys(saved_magic), %eax > + lea sym_offset(saved_magic)(%ebx), %eax > add bootsym_rel(trampoline_xen_phys_start, 4, %eax) > mov (%eax), %eax > cmp $0x9abcdef0, %eax > @@ -133,7 +135,7 @@ wakeup_32: > mov %ecx, %cr4 > > /* Load pagetable base register */ > - mov $sym_phys(idle_pg_table),%eax > + lea sym_offset(idle_pg_table)(%ebx),%eax > add bootsym_rel(trampoline_xen_phys_start,4,%eax) > mov %eax,%cr3 > > diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S > index c8bf9d0..ae4bebd 100644 > --- a/xen/arch/x86/boot/x86_64.S > +++ b/xen/arch/x86/boot/x86_64.S > @@ -81,7 +81,6 @@ GLOBAL(boot_cpu_compat_gdt_table) > .quad 0x0000910000000000 /* per-CPU entry (limit == cpu) */ > .align PAGE_SIZE, 0 > > -GLOBAL(__page_tables_start) > /* > * Mapping of first 2 megabytes of memory. This is mapped with 4kB mappings > * to avoid type conflicts with fixed-range MTRRs covering the lowest megabyte > @@ -101,21 +100,18 @@ GLOBAL(l1_identmap) > .endr > .size l1_identmap, . - l1_identmap > > -/* Mapping of first 16 megabytes of memory. */ Don't want to just update the comment? > +GLOBAL(__page_tables_start) > + > GLOBAL(l2_identmap) And perhaps explain how this page is being updated at runtime? > - .quad sym_phys(l1_identmap) + __PAGE_HYPERVISOR > - pfn = 0 > - .rept 7 > - pfn = pfn + (1 << PAGETABLE_ORDER) > - .quad (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR | _PAGE_PSE > - .endr > - .fill 4 * L2_PAGETABLE_ENTRIES - 8, 8, 0 > + .quad sym_offset(l1_identmap) + __PAGE_HYPERVISOR > + .fill 4 * L2_PAGETABLE_ENTRIES - 1, 8, 0 > .size l2_identmap, . - l2_identmap > > GLOBAL(l2_xenmap) > - idx = 0 > - .rept 8 > - .quad sym_phys(__image_base__) + (idx << L2_PAGETABLE_SHIFT) + (PAGE_HYPERVISOR | _PAGE_PSE) > + .quad 0 > + idx = 1 > + .rept 7 > + .quad sym_offset(__image_base__) + (idx << L2_PAGETABLE_SHIFT) + (PAGE_HYPERVISOR | _PAGE_PSE) > idx = idx + 1 > .endr > .fill L2_PAGETABLE_ENTRIES - 8, 8, 0 > @@ -125,7 +121,7 @@ l2_fixmap: > idx = 0 > .rept L2_PAGETABLE_ENTRIES > .if idx == l2_table_offset(FIXADDR_TOP - 1) > - .quad sym_phys(l1_fixmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l1_fixmap) + __PAGE_HYPERVISOR > .else > .quad 0 > .endif > @@ -136,7 +132,7 @@ l2_fixmap: > GLOBAL(l3_identmap) > idx = 0 > .rept 4 > - .quad sym_phys(l2_identmap) + (idx << PAGE_SHIFT) + __PAGE_HYPERVISOR > + .quad sym_offset(l2_identmap) + (idx << PAGE_SHIFT) + __PAGE_HYPERVISOR > idx = idx + 1 > .endr > .fill L3_PAGETABLE_ENTRIES - 4, 8, 0 > @@ -146,9 +142,9 @@ l3_xenmap: > idx = 0 > .rept L3_PAGETABLE_ENTRIES > .if idx == l3_table_offset(XEN_VIRT_START) > - .quad sym_phys(l2_xenmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l2_xenmap) + __PAGE_HYPERVISOR > .elseif idx == l3_table_offset(FIXADDR_TOP - 1) > - .quad sym_phys(l2_fixmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l2_fixmap) + __PAGE_HYPERVISOR > .else > .quad 0 > .endif > @@ -158,13 +154,13 @@ l3_xenmap: > > /* Top-level master (and idle-domain) page directory. */ > GLOBAL(idle_pg_table) > - .quad sym_phys(l3_bootmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l3_bootmap) + __PAGE_HYPERVISOR > idx = 1 > .rept L4_PAGETABLE_ENTRIES - 1 > .if idx == l4_table_offset(DIRECTMAP_VIRT_START) > - .quad sym_phys(l3_identmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l3_identmap) + __PAGE_HYPERVISOR > .elseif idx == l4_table_offset(XEN_VIRT_START) > - .quad sym_phys(l3_xenmap) + __PAGE_HYPERVISOR > + .quad sym_offset(l3_xenmap) + __PAGE_HYPERVISOR > .else > .quad 0 > .endif > diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c > index 8bec67f..8172520 100644 > --- a/xen/arch/x86/setup.c > +++ b/xen/arch/x86/setup.c > @@ -291,9 +291,6 @@ static void *__init bootstrap_map(const module_t *mod) > if ( start >= end ) > return NULL; > > - if ( end <= BOOTSTRAP_MAP_BASE ) > - return (void *)(unsigned long)start; > - > ret = (void *)(map_cur + (unsigned long)(start & mask)); > start &= ~mask; > end = (end + mask) & ~mask; > @@ -641,6 +638,9 @@ void __init noreturn __start_xen(unsigned long mbi_p) > > printk("Command line: %s\n", cmdline); > > + printk("Xen image base address: 0x%08lx\n", > + xen_phys_start ? xen_phys_start : (unsigned long)xen_img_base_phys_addr); > + > printk("Video information:\n"); > > /* Print VGA display mode information. */ > @@ -835,10 +835,8 @@ void __init noreturn __start_xen(unsigned long mbi_p) > uint64_t s, e, mask = (1UL << L2_PAGETABLE_SHIFT) - 1; > uint64_t end, limit = ARRAY_SIZE(l2_identmap) << L2_PAGETABLE_SHIFT; > > - /* Superpage-aligned chunks from BOOTSTRAP_MAP_BASE. */ > s = (boot_e820.map[i].addr + mask) & ~mask; > e = (boot_e820.map[i].addr + boot_e820.map[i].size) & ~mask; > - s = max_t(uint64_t, s, BOOTSTRAP_MAP_BASE); > if ( (boot_e820.map[i].type != E820_RAM) || (s >= e) ) > continue; > > @@ -876,7 +874,7 @@ void __init noreturn __start_xen(unsigned long mbi_p) > /* Select relocation address. */ > e = end - reloc_size; > xen_phys_start = e; > - bootsym(trampoline_xen_phys_start) = e; > + bootsym(trampoline_xen_phys_start) = e - xen_img_base_phys_addr; > > /* > * Perform relocation to new physical address. > @@ -886,7 +884,7 @@ void __init noreturn __start_xen(unsigned long mbi_p) > */ > load_start = (unsigned long)_start - XEN_VIRT_START; > barrier(); > - move_memory(e + load_start, load_start, _end - _start, 1); > + move_memory(e + load_start, load_start + xen_img_base_phys_addr, _end - _start, 1); > > /* Walk initial pagetables, relocating page directory entries. */ > pl4e = __va(__pa(idle_pg_table)); > @@ -895,27 +893,27 @@ void __init noreturn __start_xen(unsigned long mbi_p) > if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) ) > continue; > *pl4e = l4e_from_intpte(l4e_get_intpte(*pl4e) + > - xen_phys_start); > + xen_phys_start - xen_img_base_phys_addr); > pl3e = l4e_to_l3e(*pl4e); > for ( j = 0; j < L3_PAGETABLE_ENTRIES; j++, pl3e++ ) > { > /* Not present, 1GB mapping, or already relocated? */ > if ( !(l3e_get_flags(*pl3e) & _PAGE_PRESENT) || > (l3e_get_flags(*pl3e) & _PAGE_PSE) || > - (l3e_get_pfn(*pl3e) > 0x1000) ) > + (l3e_get_pfn(*pl3e) > PFN_DOWN(xen_phys_start)) ) > continue; > *pl3e = l3e_from_intpte(l3e_get_intpte(*pl3e) + > - xen_phys_start); > + xen_phys_start - xen_img_base_phys_addr); > pl2e = l3e_to_l2e(*pl3e); > for ( k = 0; k < L2_PAGETABLE_ENTRIES; k++, pl2e++ ) > { > /* Not present, PSE, or already relocated? */ > if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) || > (l2e_get_flags(*pl2e) & _PAGE_PSE) || > - (l2e_get_pfn(*pl2e) > 0x1000) ) > + (l2e_get_pfn(*pl2e) > PFN_DOWN(xen_phys_start)) ) > continue; > *pl2e = l2e_from_intpte(l2e_get_intpte(*pl2e) + > - xen_phys_start); > + xen_phys_start - xen_img_base_phys_addr); > } > } > } > @@ -926,10 +924,10 @@ void __init noreturn __start_xen(unsigned long mbi_p) > PAGE_HYPERVISOR_RWX | _PAGE_PSE); > for ( i = 1; i < L2_PAGETABLE_ENTRIES; i++, pl2e++ ) > { > - if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) ) > + if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) || (l2e_get_pfn(*pl2e) > PFN_DOWN(xen_phys_start))) Could this be split in two lines? > continue; > *pl2e = l2e_from_intpte(l2e_get_intpte(*pl2e) + > - xen_phys_start); > + xen_phys_start - xen_img_base_phys_addr); > } > > /* Re-sync the stack and then switch to relocated pagetables. */ > @@ -998,6 +996,9 @@ void __init noreturn __start_xen(unsigned long mbi_p) > > if ( !xen_phys_start ) > panic("Not enough memory to relocate Xen."); > + > + printk("New Xen image base address: 0x%08lx\n", xen_phys_start); > + > reserve_e820_ram(&boot_e820, __pa(&_start), __pa(&_end)); > > /* Late kexec reservation (dynamic start address). */ > @@ -1070,14 +1071,12 @@ void __init noreturn __start_xen(unsigned long mbi_p) > > set_pdx_range(s >> PAGE_SHIFT, e >> PAGE_SHIFT); > > - /* Need to create mappings above BOOTSTRAP_MAP_BASE. */ > - map_s = max_t(uint64_t, s, BOOTSTRAP_MAP_BASE); > + map_s = s; > map_e = min_t(uint64_t, e, > ARRAY_SIZE(l2_identmap) << L2_PAGETABLE_SHIFT); > > /* Pass mapped memory to allocator /before/ creating new mappings. */ > init_boot_pages(s, min(map_s, e)); > - s = map_s; > if ( s < map_e ) > { > uint64_t mask = (1UL << L2_PAGETABLE_SHIFT) - 1; > diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c > index 98310f3..baa6461 100644 > --- a/xen/arch/x86/x86_64/mm.c > +++ b/xen/arch/x86/x86_64/mm.c > @@ -44,7 +44,7 @@ unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START; > > /* Enough page directories to map into the bottom 1GB. */ > l3_pgentry_t __section(".bss.page_aligned") l3_bootmap[L3_PAGETABLE_ENTRIES]; > -l2_pgentry_t __section(".bss.page_aligned") l2_bootmap[L2_PAGETABLE_ENTRIES]; > +l2_pgentry_t __section(".bss.page_aligned") l2_bootmap[4 * L2_PAGETABLE_ENTRIES]; 16KB? ? Confused. > > l2_pgentry_t *compat_idle_pg_table_l2; > > diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S > index a399615..b666a3f 100644 > --- a/xen/arch/x86/xen.lds.S > +++ b/xen/arch/x86/xen.lds.S > @@ -38,7 +38,7 @@ SECTIONS > . = __XEN_VIRT_START; > __image_base__ = .; > #endif > - . = __XEN_VIRT_START + MB(1); > + . = __XEN_VIRT_START + XEN_IMG_OFFSET; > _start = .; > .text : { > _stext = .; /* Text and read-only data */ > diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h > index 3e9be83..6d21cb7 100644 > --- a/xen/include/asm-x86/config.h > +++ b/xen/include/asm-x86/config.h > @@ -114,6 +114,7 @@ extern unsigned long trampoline_phys; > trampoline_phys-__pa(trampoline_start))) > extern char trampoline_start[], trampoline_end[]; > extern char trampoline_realmode_entry[]; > +extern unsigned int xen_img_base_phys_addr; > extern unsigned int trampoline_xen_phys_start; > extern unsigned char trampoline_cpu_started; > extern char wakeup_start[]; > @@ -280,6 +281,8 @@ extern unsigned char boot_edid_info[128]; > #endif > #define DIRECTMAP_VIRT_END (DIRECTMAP_VIRT_START + DIRECTMAP_SIZE) > > +#define XEN_IMG_OFFSET 0x200000 > + > #ifndef __ASSEMBLY__ > > /* This is not a fixed value, just a lower limit. */ > diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h > index 87b3341..27481ac 100644 > --- a/xen/include/asm-x86/page.h > +++ b/xen/include/asm-x86/page.h > @@ -283,7 +283,7 @@ extern root_pgentry_t idle_pg_table[ROOT_PAGETABLE_ENTRIES]; > extern l2_pgentry_t *compat_idle_pg_table_l2; > extern unsigned int m2p_compat_vstart; > extern l2_pgentry_t l2_xenmap[L2_PAGETABLE_ENTRIES], > - l2_bootmap[L2_PAGETABLE_ENTRIES]; > + l2_bootmap[4*L2_PAGETABLE_ENTRIES]; ? Why do we need to expand this to be 16kB? > extern l3_pgentry_t l3_bootmap[L3_PAGETABLE_ENTRIES]; > extern l2_pgentry_t l2_identmap[4*L2_PAGETABLE_ENTRIES]; > extern l1_pgentry_t l1_identmap[L1_PAGETABLE_ENTRIES], > -- > 1.7.10.4 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel